What is AST in HST?
Hawaii Standard Time is 7 hours behind
Atlantic Time is on UTC−3:00 and Hawaii Standard Time is on UTC−10:00 right now. Atlantic Time is on daylight saving, so its clocks read ADT. The gap changes during the year — see below.
- Time in Halifax
- 11:14 pm
- Time in Honolulu
- 4:14 pm
- Difference
- −7 h
- Next clock change
- November 1, 2026
Convert a time
HST — Hawaii Standard Time
4:00 pm
Tue
When the difference changes
Atlantic Time and Hawaii Standard Time do not change their clocks on the same dates, so the gap between them is not the same all year. Most converters show only today’s figure. These are the periods ahead:
- Now – November 1, 2026Hawaii Standard Time is 7 hours behind
- November 1, 2026 – March 14, 2027Hawaii Standard Time is 6 hours behind
- March 14, 2027 – onwardsHawaii Standard Time is 7 hours behind
Periods shorter than a day are not listed: both zones change at 2am in their own local time, so there are a few hours on each transition date when the gap is briefly something else.
Daylight saving
Atlantic Time
Clocks go back one hour at 2am local time, becoming AST.
Hawaii Standard Time
Hawaii Standard Time stays on HST all year, so its offset from UTC never moves.
AST to HST conversion table
Every hour of Tuesday, September 22, 2026, converted from Atlantic Time to Hawaii Standard Time. 7 of the 24 hours fall on a different calendar day in Honolulu, which is marked.
- 12:00 am ADT
- 5:00 pm HST−1 day
- 1:00 am ADT
- 6:00 pm HST−1 day
- 2:00 am ADT
- 7:00 pm HST−1 day
- 3:00 am ADT
- 8:00 pm HST−1 day
- 4:00 am ADT
- 9:00 pm HST−1 day
- 5:00 am ADT
- 10:00 pm HST−1 day
- 6:00 am ADT
- 11:00 pm HST−1 day
- 7:00 am ADT
- 12:00 am HST
- 8:00 am ADT
- 1:00 am HST
- 9:00 am ADT
- 2:00 am HST
- 10:00 am ADT
- 3:00 am HST
- 11:00 am ADT
- 4:00 am HST
- 12:00 pm ADT
- 5:00 am HST
- 1:00 pm ADT
- 6:00 am HST
- 2:00 pm ADT
- 7:00 am HST
- 3:00 pm ADT
- 8:00 am HST
- 4:00 pm ADT
- 9:00 am HST
- 5:00 pm ADT
- 10:00 am HST
- 6:00 pm ADT
- 11:00 am HST
- 7:00 pm ADT
- 12:00 pm HST
- 8:00 pm ADT
- 1:00 pm HST
- 9:00 pm ADT
- 2:00 pm HST
- 10:00 pm ADT
- 3:00 pm HST
- 11:00 pm ADT
- 4:00 pm HST
Scheduling between the two
Working hours overlap from 4:00 pm to 6:00 pm ADT, which is 9:00 am to 11:00 am HST. Anything inside that window falls in the normal working day at both ends.
A note on AST: it can also mean Arabia Standard Time (UTC+3). This page means Atlantic Time.
Atlantic Time (ADT) is used in Nova Scotia, New Brunswick and Puerto Rico
Hawaii Standard Time (HST) is used in all of Hawaii, which does not observe daylight saving